Neck Sizing Vs. Full Length Sizing and Neck Tension

[Rosebud]

I am very new to this hobby so forgive me for asking somewhat simple questions. What is your process and equipment?? DO you bump the shoulder back with some sort of special die and then do the neck tension with what die??

ANy help greatly appreciated

Graf and sons has a foster bushing neck shoulder bump die that comes with three of the bushings that will be best for that cartridge. The bushings will determine the neck tension. Screw in the die to get the shoulder bump to allow the case to easily chamber. Works great. Around $100.

 

[Bang4theBuck]

Ok, I don't want to start a food fight or anything, but I am curious what everyone on this forum has to say about this subject. I've seen the Erik Cortina video where he says neck sizing is just passe and so much old lore, and to just full length size for consistency. I've seen some other videos on youtube which sort of cite him and say they agree. However, in my own experience, I haven't so much run the tests to match up one method against another, its just that I learned the hard way you CANNOT full length size belted magnum cartridges past 2-3 times without head case failures. At least I could not. I had 6-7 head case failures on my .300 win mag. which of course is a belted magnum. I even had one lower half stay in the chamber so tight, I had to fill it with earplugs, then fill with an epoxy, and then ram it out from the barrell end.......not fun. So, now I neck size all my new Peterson Brass and have had no more issues or failures and I'm up to 5 times on that brass. Full length sizing at least with my RCBS dies just overworked the brass shoving it back down on the belt, and then the firing would stretch it back out until it failed above the belt in case head separation due to metal fatigue. No one ever told me not to Full length size belted cartridges, no book, no article, nobody told me. I had to learn the hard way.

But, I do full length size my .338 Lapua Magnum brass every 2-4 firings now, and neck size it the rest of the time, just to try to get a little more life out of it. I think just anecdotally I see better group sizes on it when I neck size it. I haven't run any real tests yet. Is there any real scientifically consistent and valid data run by anyone you can point me to who has done exhaustive testing on this subject as to group size vs. method?

Next, I've seen some videos by sdkweber and bolt action reloading on youtube where they ran some tests that seemed to indicate that either 2 thousands or 3 thousands neck tension is optimum for shooting small groups. Is there an accepted standard in the community and if so what is it, and can you again point me to any definitive studies that are scientific, exhaustive, and consistently run that says what the answer is?
One guy says 2 thousands works best, and another seemed to end up with a relationship what shows 1 thousands is worst, 2 thousands is better and 3 thousands is best in a curvelinear line that shows diminished gains at the 3 thousands mark, ie not much to be gained if any past that.
Does anyone have a magic wand or a crystal ball?

I'm just digging in and trying to get it right!

I've often seen guys make the mistake of using the full length sizing die per the instructions with the set. First of all.....what kind da guy actually follows instructions....come on!. Just kidding. Even though the die is a full length sizing die, it is best to use the die to size as much of the brass as you can without setting the shoulder back more the a couple thousandths (.002-.003). If you screw the die all the way down as the instructions tell you, you might get .008-.012" or more of setback. That is what is killing your brass. Pretty much all of the best shooters in the world full length size. I go woth that as a standard.

Also, you don't have to use a full length sizing die to fully size the case. I happen to think that the best way for me is to use a Redding body die to size the body and set the shoulders back, and then a Lee neck collet die to set the neck dimension. I've been able to control things a little better that way.

 

[misterc01]

So new to brass (once fired or new) I full length resize. Then when it has been fireformed, I neck size it. I set the neck tension to .003. Works for me.

 

[Mike Matteson]

I have or having to change out my dies to bushing dies. They are FL presently. I set the tension by using the bushing. I have equipment to use a mandrel to expand the neck is needed.
Possible where I differner is I cut all my neck to a set thickness. I am using new unfired brass to start with. Cutting to a length then cut the neck for thickness. I remove the ball to expand the neck in the sizing process.
The funny part of it I am also including neck bushing dies now too. I'll have to see how that works out.
Presently setting up a dummy rifle to fire-form my cases, after my barrel is broke-in.

 

[C-130 Dude]

I have or having to change out my dies to bushing dies. They are FL presently. I set the tension by using the bushing. I have equipment to use a mandrel to expand the neck is needed.
Possible where I differner is I cut all my neck to a set thickness. I am using new unfired brass to start with. Cutting to a length then cut the neck for thickness. I remove the ball to expand the neck in the sizing process.
The funny part of it I am also including neck bushing dies now too. I'll have to see how that works out.
Presently setting up a dummy rifle to fire-form my cases, after my barrel is broke-in.

I would fire the new brass once or twice before cutting thickness. Just to make sure the brass settles down before I commited. But that's just me. It's all good .

 

[RUFFIAN R - NY]

Stopped neck sizing years ago now use the FL bushing dies.

 

[g7777777]

A link to all the videos mentioned would be nice. Is that allowed on this forum?

 

[Veteran]

Yes, there are several videos posted in this thread already if you go back to the beginning.

 

[SSG Graybush]

Ok, I don't want to start a food fight or anything, but I am curious what everyone on this forum has to say about this subject. I've seen the Erik Cortina video where he says neck sizing is just passe and so much old lore, and to just full length size for consistency. I've seen some other videos on youtube which sort of cite him and say they agree. However, in my own experience, I haven't so much run the tests to match up one method against another, its just that I learned the hard way you CANNOT full length size belted magnum cartridges past 2-3 times without head case failures. At least I could not. I had 6-7 head case failures on my .300 win mag. which of course is a belted magnum. I even had one lower half stay in the chamber so tight, I had to fill it with earplugs, then fill with an epoxy, and then ram it out from the barrell end.......not fun. So, now I neck size all my new Peterson Brass and have had no more issues or failures and I'm up to 5 times on that brass. Full length sizing at least with my RCBS dies just overworked the brass shoving it back down on the belt, and then the firing would stretch it back out until it failed above the belt in case head separation due to metal fatigue. No one ever told me not to Full length size belted cartridges, no book, no article, nobody told me. I had to learn the hard way.

But, I do full length size my .338 Lapua Magnum brass every 2-4 firings now, and neck size it the rest of the time, just to try to get a little more life out of it. I think just anecdotally I see better group sizes on it when I neck size it. I haven't run any real tests yet. Is there any real scientifically consistent and valid data run by anyone you can point me to who has done exhaustive testing on this subject as to group size vs. method?

Next, I've seen some videos by sdkweber and bolt action reloading on youtube where they ran some tests that seemed to indicate that either 2 thousands or 3 thousands neck tension is optimum for shooting small groups. Is there an accepted standard in the community and if so what is it, and can you again point me to any definitive studies that are scientific, exhaustive, and consistently run that says what the answer is?
One guy says 2 thousands works best, and another seemed to end up with a relationship what shows 1 thousands is worst, 2 thousands is better and 3 thousands is best in a curvelinear line that shows diminished gains at the 3 thousands mark, ie not much to be gained if any past that.
Does anyone have a magic wand or a crystal ball?

I'm just digging in and trying to get it right!

I get 15+ reloads from my belted mags, never had a case fail. a 300 wm and 7RM. Sounds like your 300 wm either has too much headspace or you bump the shoulders back too far. You should set up your FL sizer die to bump it back 2 to 4 thou back from fired.
Once the headspace is set off the belt treat belted mags like non belted cases. Headspace and bullet comparators are nesseasary tools for reloading. Most beginners read rcbs instructions and resize till slight over cam and thats wrong. Causing belted mag haters.
And measure a loaded round OD on neck, subtract 2 thou and thats where you should start for neck tension.

 

[HERMAN8R]

I would suggest that you get the Redding Competition shell holder kit. It makes bumping shoulders much easier as it allows a .002 difference and allows you to still slightly cam over on the press. Works awesome!

Good luck,
Steve

BoomFlop, I have seen mention of the shell holder kir before but did not pay much attention to it.
How is it different than adjusting the die up or down? I can see where changing the shell holder to get a setting faster without trial and error. Is that the primary function...fast, precise changes?
Sorry for my lack of knowledge on this.

 

[Louisiana Reloader]

I bump everything .002-003" at the shoulder with no issues and pockets wearing out first most of the time. Anneal every other firing and run .003" neck tension on everything. Works great for me and I am able to maintain low teens to single digit es/sd.
Tried the neck only thing was a pain to FL size every 4 or 5 firings wasnt getting any better results that I could tell. I try and keep things simple as possible. I used to be real particular about loading and all the "peace of mind things" but nowadays if i cant truly notice if it helps I dont do it.

I agree 100% with AZ-SHOOTER. I do identically the same thing with good results. I am just a deer hunter and I don't shoot for competition; however I demand 1/2 MOA out of my hunting loads. I do these things with a 6.5 PRC and I am getting .25 MOA at 300 yards. Good luck and great questions.

 

[Willys]

Thread started 2 years ago so Veteran probably has it figured out by now but great new info well worth bringing back up! Learn how to use competition shell holders gets you in the game.

 

[Veteran]

I get 15+ reloads from my belted mags, never had a case fail. a 300 wm and 7RM. Sounds like your 300 wm either has too much headspace or you bump the shoulders back too far. You should set up your FL sizer die to bump it back 2 to 4 thou back from fired.
Once the headspace is set off the belt treat belted mags like non belted cases. Headspace and bullet comparators are nesseasary tools for reloading. Most beginners read rcbs instructions and resize till slight over cam and thats wrong. Causing belted mag haters.
And measure a loaded round OD on neck, subtract 2 thou and thats where you should start for neck tension.

Please note this thread is 2 years old.....I sure have gotten a lot of good advice.....some of it the same as 2 years ago.....

 

[SSG Graybush]

Please note this thread is 2 years old.....I sure have gotten a lot of good advice.....some of it the same as 2 years ago.....

It came up as trending thread. My bad.